feat: less clone on symbol

src/ty/internal/func.rs

@@ -1,6 +1,5 @@
 use std::rc::Rc;
 
-use ecow::EcoString;
 use itertools::Itertools;
 use rpds::HashTrieMap;
 use derive_more::Constructor;
@@ -13,11 +12,11 @@ use crate::vm::{Env, VM};
 
 #[derive(Debug, Clone)]
 pub enum Param {
-    Ident(EcoString),
+    Ident(usize),
     Formals {
-        formals: Vec<(EcoString, Option<usize>)>,
+        formals: Vec<(usize, Option<usize>)>,
         ellipsis: bool,
-        alias: Option<EcoString>,
+        alias: Option<usize>,
     },
 }
 
@@ -69,7 +68,7 @@ impl<'vm> Func<'vm> {
                     && arg
                         .as_inner()
                         .iter()
-                        .map(|(k, _)| k.as_inner())
+                        .map(|(k, _)| k)
                         .sorted()
                         .ne(formals.iter().map(|(k, _)| k).sorted())
                 {
@@ -78,7 +77,7 @@ impl<'vm> Func<'vm> {
                 for (formal, default) in formals {
                     let formal = formal.clone().into();
                     let arg = arg
-                        .select(&formal)
+                        .select(formal)
                         .or_else(|| default.map(|idx| Value::Thunk(Thunk::new(vm.get_thunk(idx)))))
                         .unwrap();
                     new.insert_mut(formal, arg);